Got one i815 mobo with some kind of turboPLL mod. There is this second board cut away from another mobo and it's not very nice looking work. For example there are long wires and resistors close to mobo traces for and crystal is just put to a connector with leads... I belive this is supposed to keep PCI/AGP clocks locked while FSB is increased? Someone with more knowledge about these mods can tell me more.

Yeah, it kind of works. Floppy controller is giving me I/O error when reading. Hard drive is acting like there are bad sectors when formatting but none is marked. Got Win98SE installed fine after some HDD format attempts. I think this mod is not working perfectly. I will check what PCI&etc clocks are. Running with 1000MHz coppermine with 133FSB. Could be one thing to test dropping FSB to 100, just don't know how to do it with this mobo.
I would remove it but some caps and resistors are missing.